Messages in this thread Patch in this message | | | From | Victor Shih <> | Subject | [PATCH V12 16/23] mmc: sdhci-uhs2: add clock operations | Date | Fri, 15 Sep 2023 17:43:44 +0800 |
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From: Victor Shih <victor.shih@genesyslogic.com.tw>
This is a sdhci version of mmc's uhs2_[enable|disable]_clk operations.
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw> Acked-by: Adrian Hunter <adrian.hunter@intel.com> ---
Updates in V8: - Remove unnecessary include file. - read_poll_timeout() to instead of read_poll_timeout_atomic() in sdhci_uhs2_enable_clk(). - Put the comment on the end and put the lines in descending line length in sdhci_uhs2_enable_clk(). - Modify return value in sdhci_uhs2_enable_clk().
Updates in V6: - Remove unnecessary functions.
---
drivers/mmc/host/sdhci-uhs2.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c index 4c2a56629ab3..af1b0c5e48fd 100644 --- a/drivers/mmc/host/sdhci-uhs2.c +++ b/drivers/mmc/host/sdhci-uhs2.c @@ -329,6 +329,36 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) return 0; } +static int sdhci_uhs2_disable_clk(struct mmc_host *mmc) +{ + struct sdhci_host *host = mmc_priv(mmc); + u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + + clk &= ~SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + + return 0; +} + +static int sdhci_uhs2_enable_clk(struct mmc_host *mmc) +{ + struct sdhci_host *host = mmc_priv(mmc); + u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + int timeout_us = 20000; /* 20ms */ + u32 val; + + clk |= SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + + if (read_poll_timeout(sdhci_readw, val, (val & SDHCI_CLOCK_INT_STABLE), + 10, timeout_us, true, host, SDHCI_CLOCK_CONTROL)) { + pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc)); + sdhci_dumpregs(host); + return -EIO; + } + return 0; +} + /*****************************************************************************\ * * * Driver init/exit * -- 2.25.1
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